A 28-year-old woman with a history of intravenous drug use presents with acute onset of right hip pain, fever (39.2°C), and inability to walk. She reports injecting heroin into her right groin 5 days ago. On examination, the right hip is held in flexion, abduction, and external rotation; any attempt at internal rotation or adduction causes severe pain. Hip aspiration yields 78,000 WBC/μL (88% neutrophils), glucose 12 mg/dL (serum 110 mg/dL), protein 7.1 g/dL. Gram stain shows Gram-positive cocci in clusters. Blood cultures are positive for the same organism. What is the most appropriate next step in management?